HPE CINV Pocket Guide 2018 | Page 69

Increased exposure to orally administered CYP3A4 substrates. If co- administered with NK1 RAs, the recommended oral corticosteroid dose should be reduced by approximately 50%. Monitor for AEs with midazolam. Monitor for AEs with CT agents metabolised by CYP3A4; no need to adjust the dose Efficacy of warfarin and oral contraceptives may be decreased. Co-administration of aprepitant with active substances that are metabolised by CYP2C9 (for example phenytoin, warfarin) may result in lower plasma concentrations of these active substances. Monitor INR. Additional contraception is needed for two months Rolapitant is an inhibitor of BCRP. Increased plasma concentrations of BCRP substrates (for example methotrexate, irinotecan, topotecan, mitoxantrone, rosuvastatin, sulfasalazine, doxorubicin, bendamustine) may result in potential adverse reactions. Potential for increased exposure: monitor for AEs with substrates of CYP2D6and P-gp (for example, digoxin). No need to reduce the dose of dexamethasone. CYP2D6 participates in the metabolism of all 5-HT3 RAs, except granisetron Possibly increased likelihood of olanzapine AEs. Dose reduction of olanzapine by 25% might be required Possible decrease in efficacy of olanzapine. Monitor the occurrence of nausea and vomiting Reduced bioavailability of olanzapine (only activated charcoal) and corticosteroids. Separate administration by at least 2 h QTc interval prolongation and arrhythmias may occur. Caution is required in patients with cardiac comorbidities or with QTc prolonging drugs Possible occurrence of serotonin syndrome. Avoid interaction when possible Possibly reduced efficacy of tramadol hospitalpharmacyeurope.com | 2018 | 69